Fluorescence-based multiplexed detection and spectroscopy is finding more and more applications in analytical chemistry, molecular biology, and medical diagnostics. For example, rapid advance in genomics and proteomics research has elucidated the availability of multiple biomarkers, of which simultaneous detection allow diagnosing the complex diseases such as cancer with significantly improved accuracy in comparison with the single marker detection. Rapid, sensitive and simultaneous detection of multiple pathogens in food, in water, and in air, is essential to ensure public safety and to protect the public against potential bioterrorism. In the modern structural biology, simultaneously probing the change in distances between different sites within a larger biomolecule such as multi-subunit proteins would provide valuable information that can be utilized for the development of rational drug design and rapid vaccine development for chemical and biological countermeasures. While, the availability of high quality fluoreagents with the high and distinguished fluorescent emission is the prerequisite for all above-mentioned applications. This NIH SBIR program will develop a series of alloyed tertiary semiconductor nanocrystals that have highly bright, stable, and narrow emission, are readily to be bio-conjugated with biomolecules such as proteins and DNA, and thus can be ideally be used as fluoreagents in multiplexed detection and spectroscopy. [unreadable] [unreadable] [unreadable]